Follow Up:

Doctors still use leeches for certain delicate medical procedures (see Discover,December 2001), but the bloodsuckers have their drawbacks: They wander about while they feed, they can cause infections, and they startle patients. So medical researchers are developing mechanical surrogates that "will work better than leeches," says Nadine Connor of the University of Wisconsin.

These artificial leeches could be used after reconstructive surgery to draw off blood that collects before there is time for new veins to form.

Photograph courtesy of Jeff Miller/University of Wisconsin at Madison

Connor and her colleagues have created a device (right) with a rotating disk that slips under the skin, a tube to draw off blood, and a supply of anticoagulants. It can tap into a deeper blood supply, decongest a larger area, and remove more blood than a real leech. It also looks benign, like a tiny glass teapot with a low spout. Patrick Cottler, an independent entrepreneur, came up with an alternative leech substitute while he was a graduate student at the University of Virginia. His device consists of a small polymer box with an array of needles on one side and a blood-removing vacuum tube on the other. Both synthetic bloodsuckers could be ready for human testing within a year.